Earth's Stabilising Moon, Unique Within the Universe?

This recent photo of the moon was taken by astronauts on the International Space Station during the Expedition 24 mission mid-2010. It was posted by cosmonaut Fyodor Yurchikhin of Russia's Federal Space Agency. CREDIT: Roscosmos.


New simulations show that Earth's moon is not only unique in the solar system, but may also be rare throughout the universe.

Research reveals that less than 10 percent of terrestrial planets may have a satellite large enough to provide the stability life needs to develop.

Earth spins around its orbital axis, changing its angle toward the sun — its obliquity — by a little more than a degree over the course of thousands of years. These small differences are significant enough to cause the ebb and flow of ice ages.